Lab Manual: SURVEYING AND GEOMATICS LABORATORY ...

INSTITUTE OF AERONAUTICAL ENGINEERING(Autonomous)

Dundigal, Hyderabad - 500 043

Lab Manual:

SURVEYING AND GEOMATICS LABORATORY(ACEC05)

Prepared by

Mr. A Jagadish Babu (IARE10679)

Department Of Civil EngineeringInstitute of Aeronautical Engineering

December 20, 2021

Contents

Content iii

1 INTRODUCTION 11.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.1.1 Student Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.2 Responsibilities of Faculty Teaching the Lab Course . . . . . . . . . . . . . 11.1.3 Laboratory In-charge Responsibilities . . . . . . . . . . . . . . . . . . . . . . 11.1.4 Course Coordinator Responsibilities . . . . . . . . . . . . . . . . . . . . . . . 1

1.2 LAB POLICY AND GRADING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 COURSE GOALS AND OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . 21.4 USE OF LABORATORY INSTRUMENTS . . . . . . . . . . . . . . . . . . . . . . . 2

1.4.1 Instrument Protection Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.5 DATA RECORDING AND REPORTS . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.5.1 The Laboratory Notebook: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.5.2 The Laboratory Worksheets: . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 LAB-1 INTRODUCTION TO SURVEYING LABORATORY-I 52.1 DEFINITION: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 LAB-2 SURVEY OF AN AREA BYCHAIN SURVEY (CLOSED TRA-VERSE) AND PLOTTING 63.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.3 PRECAUTIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.4 FIGURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.5 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3.5.1 Ranging a line: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.5.2 Taking offsets: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63.5.3 Procedure for surveying the given open field (Closed Traverse): . . . . . . . 7

3.6 AREA CALCULATIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.7 RESULTS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.8 PROBING FURTHER QUESTIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 LAB-3 CHAINING ACROSS OBSTACLES 84.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.3 PRECAUTIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.4 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.5 NOMENCLATURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.6 RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.7 FURTHER PROBING EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . 10

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5 LAB-4 DETERMINE OF DISTANCE BETWEEN TWO INACCESSIBLEPOINTS WITH COMPASS 115.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.3 PRECAUTIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.4 THEORY: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.5 DESCRIPTION: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125.6 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125.7 NOMENCLATURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135.8 RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135.9 FURTHER PROBING EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . 13

6 LAB-5 SURVEYING OF A GIVEN AREA BY PRISMATIC COMPASS(CLOSEDTRAVERSE) AND P;OTTING AFTER ADJUSTMENT 146.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146.3 SPECIFICATIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146.4 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156.5 GRAPHS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156.6 TYPICAL CALCULATION: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.7 OBSERVATIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.8 RESULTS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176.9 FURTHER PROBING EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . 17

7 LAB-6 CORRECTION FOR LOCAL ATTRACTION BY PRISMATICCOMPASS. 187.1 OBJECTIVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187.3 PRECAUTIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187.4 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187.5 RESULTS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187.6 FURTHER PROBING EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . 19

8 LAB-7 RADIATION METHOD, INTERSECTION METHODS BY PLANETABLE SURVEY 208.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208.3 PRECAUTIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208.4 THEORY: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208.5 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208.6 TYPICAL TEST OBSERVATION: . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218.7 RESULTS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218.8 FURTHER PROBING EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . 22

9 LAB-8 TWO POINT PROBLEM IN PLANE TABLE SURVEY 239.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239.3 Theory: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239.4 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249.5 RESULTS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259.6 FURTHER PROBING EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . 25

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10 LAB-9 THREE POINT PROBLEM IN PLANE TABLE SURVEY 2610.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2610.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2610.3 THEORY: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2610.4 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2910.5 RESULT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

11 LAB-10 TRAVERSING BY PLANE TABLE SURVEY 3011.1 OBJECTIVE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3011.2 RESOURCES: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3011.3 PRECAUTIONS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3011.4 PROCEDURE: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3011.5 GRAPH: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3111.6 RESULTS: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3111.7 FURTHER PROBING EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . 31

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INTRODUCTION

1.1 INTRODUCTION

1.1.1 Student Responsibilities

The student is expected tocome prepared for each lab.Lab preparation includes understandingthe labexperiment from the lab manual and reading the related textbook material.

Students have to write the allotted experiment for that particular week in the work sheetsgiven and carry them to the Lab. In case of any questions or problems with the preparation,students can contact the Faculty Teaching the Lab course, but in a timely manner.

Students have to be in formal dress code, wear shoes and lab coat for the Laboratory Class.After the demonstration of experiment by the faculty, student has to perform the experiment

individually. They have to note down the observations in the observation Tables drawn in worksheets, do the calculations and analyze the results.

Active participation by each student in lab activities is expected. The student is expectedto ask the Faculty any questions they may have related to the experiment.

The student should remain alert and use commonsense while performing the lab experi-ment.They are also responsible for keeping a professional and accurate record of the labexperi-ments in the files provided.

1.1.2 Responsibilities of Faculty Teaching the Lab Course

The Faculty shall be completely familiar with each labprior to the laboratory. He/She shall pro-vide the students with details regarding the syllabus and safety review during the first week.Labexperiments should be checked in advance to make sure that everything is in working order.TheFaculty should demonstrate and explain the experiment and answer any questions posed by thestudents.Faculty have to supervise the students while they perform the lab experiments. TheFaculty is expected to evaluate the lab worksheets and grade them based on their practical skillsand understanding of the experiment by taking Viva Voce. Evaluation of work sheets has tobe done in a fair and timely manner to enable the students, for uploading them online throughtheir CMS login within the stipulated time.

1.1.3 Laboratory In-charge Responsibilities

The Laboratory In-charge should ensure that the laboratory is properly equipped, i.e., theFaculty teaching the lab receive any equipment/components necessary to perform the experi-ments.He/She is responsible for ensuring that all the necessary equipment for the lab is availableand in working condition. The Laboratory In-charge is responsible for resolving any problemsthat are identified by the teaching Faculty or the students.

1.1.4 Course Coordinator Responsibilities

The course coordinator is responsible fo rmaking any necessary corrections in Course Descriptionand lab manual. He/She has to ensure that it is continually updated and available to the students

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in the CMS learning Portal.

1.2 LAB POLICY AND GRADING

The student should understand the following policy:

ATTENDANCE: Attendance is mandatory as per the academic regulations.

LAB RECORD’s: The student must:

1. Write the work sheets for the allotted experiment and keep them ready before the beginningof eachlab.

2. Keep all work in preparation of and obtained during lab.

3. Perform the experiment and record the observations in the worksheets.

4. Analyze the resultsand get the work sheets evaluated by the Faculty.

5. Upload the evaluated reports online from CMS LOGIN within the stipulated time.

Grading Policy:

The final grade of this course is awarded using the criterion detailed in the academic regula-tions. A large portion of the student’s grade is determined in the comprehensive final exam ofthe Laboratory course (SEE PRACTICALS),resulting in a requirement of understanding theconcepts and procedure of each lab experiment for successful completion of the lab course.

Pre-Requistes and Co-Requisties:

The lab course is to be taken during the samesemester as AHSC03, but receives a separategrade. Students are required to have completed both AHSC03 and AHSC05 with minimumpassing grade or better grade in each.

1.3 COURSE GOALS AND OBJECTIVES

I The types of surveys, methods and technology involved in measuring field parameters usingtraditional and modern instruments.II The operating principles of various levelling instruments and analyze their performance char-acteristics under various terrains.III The measurement of alteration works, detecting land use and land cover, creating base mapsfor visual reference.

1.4 USE OF LABORATORY INSTRUMENTS

One of the major goals of this lab is to familiarize the student with the proper equipmentandtechniques for conducting experiments. Some understanding of the lab instruments is neces-saryto avoid personal or equipment damage.By understanding the device’s purpose and followinga fewsimple rules, costly mistakes can be avoided.

The following rules provide a guideline for instrument protection.

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1.4.1 Instrument Protection Rules

1. New students must receive an orientation on lab operating procedures before working ina lab.

2. Students shall publish a safety checklist for equipment for which they are responsible.

3. Students must read the safety checklist for each piece of equipment before operating it.

4. Ensure you know the location of the emergency stop button before starting equipment.

5. Always depressurize accumulators or pneumatic reservoirs before working on fluid powerapparatus.

6. Check the application pressure, system pressure, and component pressure before connect-ing a system to a pump or pressure source. The maximum operating pressures are listedon equipment labels or published on manufacturer websites.

7. Periodically check hoses for leakage, cracks, kinks, or breaks.

8. Test your equipment for leaks at low pressure before raising the pressure to the operatingpressure.

9. All components shall operate within manufacturer’s specifications.

10. Equipment shall incorporate an emergency stop or emergency return control, whicheverprovides maximum safety.

11. Emergency stops shall be readily accessible under all conditions of working and shalloperate immediately.

12. Equipment shall be designed so that loss of electrical, pneumatic and/or hydraulic powershall not cause a hazard.

13. Pump inlet temperatures should not exceed 600C when maximum ambient temperaturesexist.

14. Rotating parts shall be guarded to provide adequate protection against hazard.

15. Flexible hoses shall only be used where necessary. Their length shall be minimized and theyshall be protected from abrasion. If failure causes a hazard, the hose shall be restrainedor shielded.

1.5 DATA RECORDING AND REPORTS

1.5.1 The Laboratory Notebook:

Students must record their experimental values in the provided tables in this laboratory manualand reproduce them in the lab reports. Reports are integral to recording the methodology andresults of an experiment. In engineering practice, the laboratory notebook serves as an invalu-able reference to the technique used in the lab and is essential when trying to duplicate a resultor write a report. Therefore, it is important to learn to keep accurate data. Make plots of dataand sketches when these are appropriate in the recording and analysis of observations. Notethat the data collected will be an accurate and permanent record of the data obtained duringthe experiment and the analysis of the results. You will need this record when you are ready toprepare a lab report.

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1.5.2 The Laboratory Worksheets:

Reports are the primary means of communicating your experience and conclusions to other pro-fessionals. In this course you will use the lab report to inform your LTA about what you didand what you have learned from the experience. Engineering results are meaningless unless theycan be communicated to others. You will be directed by your LTA to prepare a lab report ona few selected lab experiments during the semester. Your assignment might be different fromyour lab partner’s assignment.Your laboratory report should be clear and concise. The lab report shall be typed on a wordprocessor. As a guide, use the format on the next page. Use tables, diagrams, sketches, andplots, as necessary to show what you did, what was observed, and what conclusions you can drawfrom this. Even though you will work with one or more lab partners, your report will be theresult of your individual effort in order to provide you with practice in technical communication.

CONCLUSIONS - The conclusion section should provide a take-home message summingup what has been learned from the experiment:

1. Briefly restate the purpose of the experiment (the question it was seeking to answer)

2. Identify the main findings (answer to the research question)

3. Note the main limitations that are relevant to the interpretation of the results

4. Summarise what the experiment has contributed to your understanding of the problem.

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LAB-1 INTRODUCTION TO SURVEYING LABORATORY-I

2.1 DEFINITION:

Surveying is the science and art of making all essential measurements to determine the relativeposition of points or physical and cultural details above, on, or beneath the surface of the Earth,and to depict them in a usable form, or to establish the position of points or details.1. Introduction to principle of surveying2. Introduction to chain surveying and their components, types of chains, errors in chain sur-veying, corrections for chain surveying, principles and procedures.3. Introduction to tape surveying and their components, types of tapes, errors in tape surveying,corrections for tape surveying, principles and procedures.4. Introduction to compass surveying and their components, types of compass, errors in com-pass, corrections for local attraction, principles and procedures.5. Introduction to plane table surveying and their components, types of plane tables.6. Introduction to leveling instruments and their components, types of leveling instruments,correction for curvature and refraction.7. Introduction to contours, types of contours and methods of plotting contours.8. Introduction to plot longitudinal section and cross section.

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LAB-2 SURVEY OF AN AREA BYCHAIN SURVEY (CLOSEDTRAVERSE) AND PLOTTING

3.1 OBJECTIVE:

To survey an open field by chain survey in order to calculate an area of the field.

3.2 RESOURCES:

To study the gyroscopic effect of a rotating disc.

3.3 PRECAUTIONS:

1. Chainages must be marked against the working edge of the offset scale.

2. The plan must be so oriented on the sheet that the north side of the survey lies towardsthe top of the sheet.

3. Each triangle must be verified by measuring the check lines.

3.4 FIGURE:

3.5 PROCEDURE:

3.5.1 Ranging a line:

It is the process of establishing a number of intermediate points on a survey line joining twostations in the field, so that all the points on the line are in alignment and the length betweenstations may be measured accurately. Two ranging rods are erected vertically at the end stationsby two surveyors who are standing behind ranging rods. One of the surveyors from one of theend stations directs the assistant to hold the ranging rod vertically to establish an intermediatepoint and move the rod either to the left or right until the ranging rod is in alignment with theend stations. Finally, when the ranging is correct, the assistant is directed to fix the rangingrod at that point. All the directions from surveyor should be as per the Code of Signals givenin Table 1.

3.5.2 Taking offsets:

The perpendicular distance measured right or left of the chain line to locate the details likecorners, boundaries, culverts, etc is known as offset. Offsets can be taken by two ways: 1. ByTape and 2. By Cross-Staff.

By Tape:The leader holds the zero end of the tape at the point where the offset is to be taken and

the follower swings off the tape in an arc across the chain line to left and right. The minimum

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reading of tape on the chain line gives the position of the foot of the perpendicular from therequired point.

By Cross-Staff:The Cross-Staff is held vertically on the chain line approximately near the point where the

offset is likely to fall. The Cross-Staff is turned until the signal at one end of the chain line isviewed through one pair of slits. The surveyor then takes a round and views through the otherpair of silts. If the point to which the offset is to be taken is seen, the point below the instrumentis the required foot of the offset. On the other hand, if the point is not seen, the surveyor movesalong the chain line, without twisting the CrossStaff, till the point appears.

3.5.3 Procedure for surveying the given open field (Closed Traverse):

ABCDEF is the required closed traverse open field to be surveyed for calculating the area asshown in Fig 1. From the station A the length of all the opposite corners such as AC, AD andAE are measured with a chain and the longest distance is considered for laying off the mainchain line. In this case AD is the longest and a chain line running from A to D is laid. Offsetsto corner points B, C, E and F are now laid from the chain line AD either by tape or cross-staffand their foot of offsets are G, I, J, H respectively. All the offset lengths GB, HF, IC and JEare measured either by chain or tape depending on the length of offsets. The distances betweenall the points AG, GH, HI, IJ and JD are also measured along the chain line

3.6 AREA CALCULATIONS:

3.7 RESULTS:

The total Area of the given Open Field by Chain Survey = ..............sqm

3.8 PROBING FURTHER QUESTIONS:

1. How the offsets are taken in the field?

2. What are the precautions are to be taken in erecting perpendiculars?

3. What is indirect ranging and how it can be done?

4. What is base line and check line?

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LAB-3 CHAINING ACROSS OBSTACLES

4.1 OBJECTIVE:

CONDITIONS FOR STATIC BALANCING:

If a shaft carries a number of unbalanced masses such that the center of mass of the systemlies on the axis of rotation, the system is said to staticallybalance.

BALANCING OF SEVERAL MASSES ROTATING IN DIFFERENTPLANES:

When several masses revolve in different planes, they may be transferred to a reference plane(written as RP), which may be defined as the plane passing through a point on the axis of ro-tation and perpendicular to it. The effect of transferring a revolving mass (in one plane) to areference plane is to cause a force of magnitude equal to centrifugal force of the revolving massto act in the reference plane, together with a couple of magnitude equal to the product of theforce and the distance between the plane of rotation and the reference plane. In order to havea complete balance of the several revolving masses in different planes, the following conditionsmust be satisfied:1. The forces in the reference plane must balance, i.e. the resultant force must bezero.2. The couple about the reference plane must balance, i.e. the resultant couple must be zero.Let us now consider four masses m1, m2, m3 and m4 revolving in planes 1, 2, 3 and 4 shown infig. The relative angular positions of these masses are shown in the end viewFig. The magnitude, angular position and position of the balancing mass m1in plane 1may beobtained as discussed below:1. Take one of the planes, say 1as the reference plane (R.P.). The distance of all the other planesto the left of the reference plane may be regarded as negative, and those to the right aspositive.2. Tabulate the data as in table. The planes are tabulated in the same order i.e. 1, 2, RP

4.2 RESOURCES:

To balance the masses statically of a simple rotating mass system and to observe the effect ofunbalance in a rotating mass system.

4.3 PRECAUTIONS:

Study about rotating balancing system

4.4 PROCEDURE:

1. Insert all the weights in sequence 1- 2- 3 - 4 from pulleyside.

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2. Fix the pointer and pulley onshaft.

3. Fix the pointer on θ o (θ2) on the circular protractorscale.

4. Fix the weight no. 1 in horizontalposition.

5. Rotate the shaft after loosening previous position of pointer and fix it onθ3.

6. Fix the weight no. 2 in horizontal position.

7. Loose the pointer and rotate the shaft to fix pointer onθ4.

8. Fix the weight no. 3 in horizontal position.


10. Fix the weight no.4 in horizontal position.

11. Now the weights are mounted in correctposition.

12. For static balancing, the system will remain steady in any angularposition.

13. Now put the belt on the pulleys of shaft and motor.

14. Supply the main power to the motor through dimmerstat.

15. Gradually increase the speed of the motor. If the system runs smoothly and withoutvibrations, it shows that the system is dynamically balanced.

16. Gradually reduce the speed to minimum and then switch off the main supply to stopthesystem.

4.5 NOMENCLATURE:

L = Distance between particular weight from weight 1, mm W = Mass of particular weight, kgθ = Angle of particular weight from Reference Point, degree

4.6 RESULTS

Obstacles to measurement:Obstructed length from First Method = mObstructed length from Second Method = mObstructed length from Third Method = mObstacles to alignment:Obstructed length from First Method = m

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4.7 FURTHER PROBING EXPERIMENTS

1. Write the importance of balancing?

2. Differentiate: static and dynamic balancing.

3. Can a single cylinder engine be fully balanced? Why?

4. Define tractive force.

5. What are the effects of hammer blow and swaying couple?

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LAB-4 DETERMINE OF DISTANCE BETWEEN TWO INAC-CESSIBLE POINTS WITH COMPASS

5.1 OBJECTIVE:

CONDITIONS FOR DYNAMICBALANCING:If a shaft carries a number of unbalanced masses such that the center of mass of the system lieson the axis of rotation, the system is said to statically balance. The resultant couple due to allthe inertia forces during rotation must bezero.These two conditions together will give complete dynamic balancing. It is obvious that a dy-namically – balanced system is also statically balanced, but the statically balanced system isnot dynamically balanced.

5.2 RESOURCES:

To balance the masses Statically & Dynamically of a simple rotating mass system and to observethe effect of unbalance in a rotating mass system.

5.3 PRECAUTIONS:

This experiment is to be fusion of two pieces of metal by an electric arc between the pieces beingjoined. So, the working of Arc welding machine and the components available for the machineand procedure of the manufacture. So how the welding is been done can be studied on courseAMEB05 so before doing the experiment be prepared with the prelab preparation of welding/joining.

5.4 THEORY:

BALANCING OF SEVERAL MASSES ROTATING IN DIFFERENTPLANES:When several masses revolve in different planes, they may be transferred to a reference plane(written as RP), which may be defined as the plane passing through a point on the axis ofrotation and perpendicular to it. The effect of transferring a revolving mass (in one plane) to areference plane is to cause a force of magnitude equal to centrifugal force of the revolving massto act in the reference plane, together with a couple of magnitude equal to the product of theforce and the distance between the plane of rotation and the reference plane. In order to havea complete balance of the several revolving masses in different planes, the following conditionsmust be satisfied:‘

1. The forces in the reference plane must balance, i.e. the resultant force must bezero.

11

2. The couple about the reference plane must balance, i.e. the resultant couple must be zero.

Let us now consider four masses m1, m2, m3 and m4 revolving in planes 1, 2, 3 and 4 shown infig. The relative angular positions of these masses are shown in the end viewFig. The magnitude, angular position and position of the balancing mass m1in plane 1may beobtained as discussed below:

1. Take one of the planes, say 1as the reference plane (R.P.). The distance of all the otherplanes to the left of the reference plane may be regarded as negative, and those to theright aspositive.

2. Tabulate the data as in table. The planes are tabulated in the same order i.e. 1, 2,3.RP

5.5 DESCRIPTION:

The apparatus consists of a steel shaft mounted in ball bearings in a stiff rectangular mainframe. A set of four blocks of different weights is provided and may be detached from the shaft.A disc carrying a circular protractor scale is fitted to one side of the rectangular frame. A scale isprovided with the apparatus to adjust the longitudinal distance of the blocks on the shaft. Thecircular protractor scale is provided to determine the exact angular position of each adjustableblock. The shaft is driven by electric motor mounted under the main frame, through a belt.For static balancing of weights the main frame is suspended to support frame by chains thenrotate the shaft manually after fixing the blocks at their proper angles. It should be completelybalanced. In this position, the mo for dynamic balancing of the rotating mass system, the mainframe is suspended from the support frame by two short links such that themain frame and thesupporting frame are in the same plane. Rotate the statically balanced weights with the helpof motor. If they rotate smoothly and without vibrations, they are dynamically balanced ordriving belt should be removed.

5.6 PROCEDURE:

1. Insert all the weights in sequence 1- 2- 3 - 4 from pulleyside.

2. Fix the pointer and pulley onshaft.

3. Fix the pointer on θ o (θ2) on the circular protractorscale.


5. Rotate the shaft after loosening previous position of pointer and fix it onθ3.





10. Fix the weight no.4 in horizontalposition.

11. Now the weights are mounted in correctposition.

12. For static balancing, the system will remain steady in any angularposition.

12

13. Now put the belt on the pulleys of shaft andmotor.

14. Supply the main power to the motor throughdimmerstat.

15. Gradually increase the speed of the motor. If the system runs smoothly and withoutvibrations, it shows that the system is dynamicallybalanced.

16. Gradually reduce the speed to minimum and then switch off the main

17. supply to stop the system.

5.7 NOMENCLATURE:

L = Distance between particular weight from weight 1, mm W = Mass of particular weight, kgθ = Angle of particular weight from Reference Point, degree

5.8 RESULTS

The distance between the two inaccessible points A and B = m


1. Write the importance ofbalancing?

2. Differentiate: static and dynamicbalancing.

3. Can a single cylinder engine be fully balanced?Why?

4. Define tractiveforce.

5. What are the effects of hammer blow and swayingcouple?

13

LAB-5 SURVEYING OF A GIVEN AREA BY PRISMATICCOMPASS(CLOSED TRAVERSE) AND P;OTTING AFTERADJUSTMENT

6.1 OBJECTIVE:

To Determine the Balancing Forces and Reciprocating MassessectionEquipment needed

� Reciprocating Masses Test rig

6.2 RESOURCES:

The Mathematical analysis of the behavior of journal in a bearing falls into two distinct cate-gories as given in the appendix of this manual. They are,1) Hydrodynamics of fluid flow between plates.2) Journal bearing analysis where the motion of the journal in the oil film is considered.According to equation the Somerfield pressure function (When the velocity of the eccentricityand the whirl speed of the journal are both zero) is given byWhere P is the pressure of the oil film at the point measured clockwise from the line of commoncenters (00)̈ andP = P0 at θ = 0 and θ = π refer the fig.Note: – Some books on lubrication give the Summerfield function with a negative sign for n.This is true if it is measured from the point of minimum thickness of the oil film that is

h = δ(1 − nCosθ)

It is also proved in the analysis that maximum pressure occurs at

Cosθm =3m

2 + n2

6.3 SPECIFICATIONS:

1. DiameterofJournal = ( A ) = 2R =55mm

2. Diameterofbearing = ( E ) = 2r = 70mm (With 16 radialtapings)

3. Bearingwidth = ( L ) =15mm

4. Weight of bearing withattachment= 1.7 kg

5. Weight ofbalancingload = ( J )=

6. Set of weights isprovided.

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7. MotorD. C. = 0.5 HP, 1500 rpm. Variable speed.

8. Dimmer state is provided for speed variation.

9. Manometer board with 16 tubes and suitable height with suitable scales and adjustableoil tank.

10. Recommendedoil = Lubricating oil SAE 20 or SAE30.

11. Supplyrequired = A. C., 1 HP, 230 V., 50 c/sec., stabilized.

6.4 PROCEDURE:

1. Fill the oil tank by using SAE 20 or SAE 30 lubricating oil under test and position thetank at the desiredheight.

2. Drain out the air from all the tubes on the manometer and check level balance with supplylevelIndicator.

3. Check that some oil leakage is there. Some leakage of oil is necessary for cooling purpose.

4. Check the direction of rotation and increase the speed of the motorslowly.

5. Set the speed and let the journal run for about half an hour until the oil in the bearing iswarmed up and check the steady oil levels at varioustapings.

6. Add the required loads and keep the balancing rod in horizontal position by moving bal-ancing weight ”J” on the rod and observe the steadylevels.

7. When the manometer levels have settled down, take the pressure readings on 1 to 12manometer tubes. For circumferential pressure distribution and A-B-12-C-D tubes foraxial pressuredistribution.

8. Repeat the experiment for various speeds and loads.

9. After the test is over set dimmer to zero position and switch off mainsupply.

10. Keep the oil tank at lower most position so that there will be no leakage in the idleperiod.

6.5 GRAPHS:

1. Graph to be plotted for pressure head of oil above supply head in cm. of oil, at an-gular intervals of 300 of oil film. The angular interval position are measured clockwise,commencing with position marked ”1” inFig.

2. Graph is drawn for theoretical and experimental pressure curves for journal N1 = NRPM.

3. Graph is plotted for experimental pressure curves along the length of bearing at thesespeeds.

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6.6 TYPICAL CALCULATION:

These calculations are based on sample readings and will differ from actual results and calcula-tions for different unit. Data used in calculation is not pertaining to the actual unit supplied.The method of drawing the theoretical Somerfield pressure curve is as follows: Consider pressurecurve for N1 = N RPM.

� Select two points A and B on the experimental pressure curve of equal pressure and1800apart.

� Note that for any pressure curve there will be only one such pair of points is possible.These two points A and B from the axisP–P0 = 0for the Somerfieldcurve.

� Of these two points take the point which is maximum thickness of oil film and take θ = 0to pass through thispoint.

� From the graph determine the point of maximum pressure ( P – P0 ) max. in thiscaseθ = 2060 = −3n/2 + n2 n = 0.8

Also 176 =−Ksin2060(2 + 0.8Cos2060)

1 + 0.8Cos2060k=24.5

� Now plot the curve P - P0=(with B as origin)

Load on the bearingTotal vertical load on bearing at NRPM.= Dry weight of Bearing + Weight added + Weight of balancing load.= 1.375 + 2 x 0.150 + added weight nil.= 1.675 Kg.Referring to fig. the mean positive pressure head of the oil above supply head.= (35.5 + 24 +18 + 12 + 8+ 5 + 2 + 60 + 177 + 130) /10.= 45.5 cm.Load carried by oil pressure on projected area of bearing= 45.5 x Density of oil x (2 R) L.= 45.5 x 0.8539 x 5.5 x 6.8.= 1.450 kg.The underlined figures are recorded from graph and balanced are practical result.Maximum theoretical load on journal is Table 1:Typical Results w. r. t. manometer tubes.

Table 2: PRESSURE HEAD OF OIL FILM ABOVE HEAD = (P – Ps) cm.Shaft speed= RPM.

6.7 OBSERVATIONS:

The Somerfield pressure function agrees with the experimental pressure curve within reasonablelimits as indicated in Fig. Any deviations between the experimental and theoretical curves canbe due to –

1. Human error in taking readings, for example in deciding whether or not the oil levels inthe manometer are absolutely steady before takingreading.

16

2. The theoretical analysis is based on the assumption that the thickness of the oil filmh = δ + eCosθ which is true only if the radial clearance is very small. In practical journalbearings this assumption is true but in this test rig θ= 2.5 mm. which is very large. Thishas been purposely done so that the oil film profile is clearlyvisible.

3. The total weight of the bearing is = 1.375 Kg. It can be seen that the oil film in thebearing does not carry this full weight, a part of weight appears to be taken by the seal,and the flexible plastic tubes attached to thebearing.

6.8 RESULTS:

Distances:AB = mBC = mCD = mDE = mEA = mIncluded Angles:Angle A =Angle B =Angle C =Angle D =Angle E =


1. The journal bearings are generally usedin.

2. The basic type of motion of a body is not the translation motiononly.

3. Coplanar forces are not easily simplified in the simplification of the force and couple systemin the calculations of forces in the journalbearings.

4. The moment of the force is the product of the force and the perpendicular distance of theaxis and the point of action of the force. Is this also true for rolling?

5. If a car is moving forward, what is the direction of the moment of the moment caused bythe rolling of the tires, assume non slipperysurface?

17

LAB-6 CORRECTION FOR LOCAL ATTRACTION BY PRIS-MATIC COMPASS.

7.1 OBJECTIVE

To study the longitudinal vibration of helical spring and to determine the frequency and timeperiod of oscillation theoretically and actually by experiment.

7.2 RESOURCES:

Get complete detail of Springs and there stiffness and also how test rig works

7.3 PRECAUTIONS:

1. The plan must be so oriented on the sheet that the north side of the survey lies towardsthe top of the sheet

2. Temporary adjustments must be done carefully.

3. Compass readings must be taken with full accuracy

4. Care must be taken while centering the compass

7.4 PROCEDURE:

1. Fix one end of the helical spring to upperscrew.

2. Determine freelength.

3. Put some weight to platform and note down thedeflection.

4. Stretch the spring through some distance andrelease.

5. Count the time requiredin Sec. for say 10, 20 oscillations.

6. Determine the actualperiod.

7. Repeat the procedure for differentweights.

7.5 RESULTS:

Distances:AB = mBC = mCD = m

18

DE = mEA = mIncluded Angles:Angle A =Angle B =Angle C =Angle D =Angle E =


1. When a body is subjected to transverse vibrations, the stress induced in a body willbe?

2. The ratio of the maximum displacement of the forced vibration to the deflection due tothe static force is knownas.

3. The natural frequency (in Hz) of free longitudinal vibrations is equalto?

4. Define resonance. When a body is subjected to transverse vibrations, the stress inducedin a body will be?

5. The ratio of the maximum displacement of the forced vibration to the deflection due tothe static force is known as.

6. The natural frequency (in Hz) of free longitudinal vibrations is equalto?

7. Define resonance.

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LAB-7 RADIATION METHOD, INTERSECTION METHODSBY PLANE TABLE SURVEY

8.1 OBJECTIVE:

To determine the frequency of different shafts.

8.2 RESOURCES:

1. Tape Linen Tape 20m

2. Ranging Rods 3m or 2m

3. Arrows

4. Plane Table with Tripod and its accessories

5. Two Drawing Sheets

6. Drawing Clips

7. Pencil, Eraser and Pins

8.3 PRECAUTIONS:

1. The plan must be so oriented on the sheet that the north side of the survey lies towardsthe top of the sheet

2. Leveling must be done carefully.

3. Readings must be taken with full accuracy

4. Ground points must be transferred to paper with full accuracy

8.4 THEORY:

SHAFT SUPPLIED WITH THE EQUIPMENT:Polishing spring steel shafts are supplied with the machine, the dimensions being as under,

8.5 PROCEDURE:

At motor end as well as tail end different bearing blocks can be fixed which are as follows,

1. Supported end condition – Make use of end block with single self aligningbearing.

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2. Fixed end conditionx – Make use of end block with doublebearing.

3. Guards D1, D2 and D3 –

4. The guards can be fixed at any position on the supporting frame which fits on the sidesupports. Rotating shafts are to be fitted in blocks in A and B stands.

5. SPEED CONTROL OF DRIVING MOTOR –

6. The driving motor is 240 volts, frictional HP, 5000 rpm, 50 Hz, and speed control unit isa Dimmerstat of 240 volts, 2 Amp. 50Hz.

7. MEASUREMENT OF SPEED –

8. To measure the speed of the rotating shaft a simple Tachometer may be used (will not besupplied with the equipment) on the opposite side of the shaft extension of the motor.

9. Whirling of elastic shaft –

10. If, L = Length of the shaft incm.

11. E = Young’s Modulus Gpa = 73 in torsion and 193Gpa in tension I = 2nd moment ofinertia of the shaft cm4.

12. W = Weight of the shaft per unit length Kg /cm. g = Acceleration due to gravity in m /sec2 = 9.81

13. Then the frequency of vibration for the various modes is given by the equation, f =kx√

EIg

8.6 TYPICAL TEST OBSERVATION:

1. Both ends of shafts free (Support) 1st and 2nd mode of vibration can be observed on shaftswith 3/16”: dia. And ¼”dia.

2. One end of shaft fixed and the other free, 1st and 2nd mode of vibration can be observedon the shaft with 3/16”dia.

3. Both ends of shaft fixed – 2nd mode of vibration cannot be observed on any of the shaftsas the speeds are very high and hence beyond the range of theapparatus.

4. There is difference between theoretical speed of whirling and actual speed observed, dueto following reasons:

(a) The end conditions are not as exact as assumed intheory.

(b) Pressure of damping at the endbearings.

(c) Assumptions made in theoreticalpredictions.

(d) Lack of knowledge of exact properties of shaftmaterial.

(e) A uniformly loaded shaft has, theoretically infinite no. of natural frequencies oftransverse vibration for fundamental mode observation of the first mode of whirlingis therefore not so defined and thus difficult 2nd can be very easilyobserved.

8.7 RESULTS:

Given area is plotted on paper by Radiation and Intersection methods of Plane Table Survey.

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1. Define time period related to vibratorymotion.

2. Define time cycle related to vibratorymotion.

3. Name different types of freevibrations.

4. Define longitudinalvibrations.

5. Name different types ofvibrations

22

LAB-8 TWO POINT PROBLEM IN PLANE TABLE SURVEY

9.1 OBJECTIVE:

To Study the Double Slider Crank and Geneva Mechanism

9.2 RESOURCES:

Double Slider CrankMechanismGenevaMechanism

9.3 Theory:

DOUBLE SLIDER CRANK MECHANISMDouble Slider Crank Chain A four bar chain having two turning and two sliding pairs such thattwo pairs of the same kind are adjacent is known as double slider crank chain.Inversions of Double slider Crank chain: It consists of two sliding pairs and two turning pairs.They are three important inversions of double slider crank chain. 1) Elliptical trammel. 2)Scotch yoke mechanism. 3) Oldham

”s Coupling.

1. Elliptical Trammel:This is an instrument for drawing ellipses. Here the slotted link is fixed. The sliding block Aand B in vertical and horizontal slots respectively. The end R generates an ellipse with thedisplacement of sliders A and B.

The co-ordinates of the point R are x and y. From the fig. cosθ = x. OR and Sinθ = y.OQSquaring and adding (i) and (ii) we getThe equation is that of an ellipse, hence the instrument traces an ellipse. Path traced2. Scotch yoke mechanism: This mechanism, the slider A is fixed. When AB rotates aboveA, the slider B reciprocates in the vertical slot. The mechanism is used to convert rotary toreciprocating mechanism. Consider fig a and b.GENEVA MECHANISMINTRODUCTIONThe Geneva drive or Maltese cross is a gear mechanism that translates a continuous rotationmovement into intermittent rotary motion. The rotating drive wheel is usually equipped witha pin that reaches into a slot located in the other wheel (driven wheel) that advances it by onestep at a time.

CLASSIFICATION OF GENEVA MECHANISM

1. External Gear MechanismIn this type of mechanism, the Geneva cross is connected with cam drive externally which is themost popular and can withstand higher mechanical stresses. The driver grooves lock the driven

23

wheel pins during dwell. During movement, the driver pin with the driver-wheel slot.

2. Internal Gear MechanismIn this type of mechanism the Geneva cross and cam drive are connected internally in the closedbox. The driver and driven wheel rotate in same direction. The duration of dwell I more the180o of driver rotation.

3. Spherical Geneva MechanismIn this type of mechanism, the Geneva cross is in spherical shape and cam drive is connectedin externally, which is extremely rare. The driver and driven wheel are on perpendicular shafts.The duration of dwell is exactly 180o of driven rotation.

Working of Geneva MechanismIn the most common arrangement, the driven wheel has four slots and thus advances by onestep of 90 degree for each rotation of the drive wheel. If the driven wheel has n slots, it advancesby 360 degree per n full rotation of the drive wheel.Geneva are also combined with variety of other mechanism, such as four bar linkages, clutch-brake combination, Non- circular gears etc to modify the motion curves and dwell motion ratiosobtained from pure Geneva.perpendicular shafts. The duration of dwell is exactly 180o of driven rotation.Advantages of Geneva Mechanisma) Geneva Mechanism may be the simplest and least Expensive of all intermittent motion mech-anism.b) They come in a wide variety of sizes, ranging from those used in instrument, to those usedin machine tools to index spindle carriers weighing several tons.c) They have good motion curves characteristics compared to ratchets, but exhibit more “jerk”or instantaneous change in acceleration, than better cam systems.Disadvantages of Geneva Mechanisma) The Geneva is not a versatile mechanism and produce jerk.b) The ratio of dwell period to motion is also established once the no of dwells per revolutionhas been selected.c) All Geneva acceleration curves start and end with finite acceleration and deceleration.Application of Geneva Mechanism� It is applicable in the production industries and automobile industries for mass production.� Modern film projectors may also use an electronically controlled indexing mechanism or step-per motor, which allows for fast-forwarding the film.� Geneva wheels having the form of the driven wheel were also used in mechanism watches, butnot in a drive, rather to limil the tension of the spring, such that it would operate only in therange where its elastic force is nearly linear.� Indexing table in assembly lines, tool changers for CNC machine, and so on.

9.4 PROCEDURE:

In this method two stations are so selected that all the other stations to be plotted are visiblefrom these. The line joining these two stations is called Base Line. The length of this line ismeasured very accurately. Rays are drawn from these stations to the stations to be plotted.The intersection of the rays from the two stations gives the position of the station to be plottedon the drawing sheet. Let A and B be the two accessible stations (Fig 3), such that A and Bcan be suitably plotted. C is the station to be plotted by intersection. The plane table is placedat A. N – S direction is plotted. The ground station A is transferred as

”a onto the drawing

24

sheet. With the alidade centered at , station B is sighted. A ray aB is drawn and is cut as abto a suitable scale. With the alidade at , C is also sighted and a ray aC is drawn. The table isnow shifted to B and is setup. The alidade is placed at b and C is sighted. A ray bC is drawn.The intersection of the two rays gives the position of C as on the plane table

9.5 RESULTS:

The required instrument station C is occupied by using two point problems


1. Define machine & structure.

2. Concept of kinematics links, pairs, chains & mechanism.

3. Classification & examples of all the kinematics links, pairs, chains & mechanism.

4. Grashof’s criterion.

5. Types & examples of constrained motion.

25

LAB-9 THREE POINT PROBLEM IN PLANE TABLE SUR-VEY

10.1 OBJECTIVE:

To find the required stations by using three point problem.

10.2 RESOURCES:

Write the text here

10.3 THEORY:

FUNCTION OF TRANSMISSION BOX (GEAR BOX) IN AUTOMOBILE:The transmission box which is also known as the gear box is the second element of the powertrain in an automobile. It is used to change the speed and torque of vehicle according to vari-ety of road and load conditions. Transmission box change the engine speed into torque whenclimbing hills and when the vehicle required. Sometimes it is known as torque converter. Mainfunctions of a gear box are as follow:1. Provide the torque needed to move the vehicle under a variety of road and load conditions.It does this by changing the gear ratio between the engine crankshaft and vehicle drive wheels.2. Be shifted into reverse so the vehicle can move backward.3. Be shifted into neutral for starting the engine.MAIN COMPONENTS OF A GEAR BOX:In any device two or more component works together and full fills the required function. In atransmission box four components are required to fulfil its function. These components are-

a) Counter shaft:Counter shaft is a shaft which connects with the clutch shaft directly. It contains the gear whichconnects it to the clutch shaft as well as the main shaft. It may be run at the engine speed orat lower than engine speed according to gear ratio.

b) Main shaft:It is the shaft which runs at the vehicle speed. It carries power from the counter shaft by use ofgears and according to the gear ratio, it runs at different speed and torque compares to countershaft. One end of this shaft is connects with the universal shaft.

c) Gears:Gears are used to transmit the power from one shaft to another. They are most useful compo-nent of gear box because the variation is torque of counter shaft and main shaft is depends onthe gear ratio. The gear ratio is the ratio of the driven gear teeth to the driving gear teeth. Ifgear ratio is large than one, the main shaft revolves at lower speed than the counter shaft and

26

the torque of the main shaft is higher than the counter shaft. On other hand if the gear ratiois less than one, than the main shaft revolves at higher speed than the counter shaft and thetorque of the main shaft is lower than the counter shaft. A small car gear box contains fourspeed gear ratio and one reverse gear.

d) Bearings:Whenever the rotary motion encounters, bearings are required to support the revolving part andreduce the friction. In the gear box both counter and main shaft are supported by the bearing.

WORKING OF A PRINCIPLE GEAR BOX:In a gear box, the counter shaft is mashed to the clutch with a use of a couple of gears. So thecounter shaft is always in running condition. When the counter shaft is bring in contact withthe main shaft by use of meshing gears, the main shaft start to rotate according to the gearratio. When driver want to change the gear ratio, simply press the clutch pedal which discon-nect the counter shaft with engine and connect the main shaft with counter shaft by anothergear ratio by use of gearshift lever. In an gear box, the gear teeth and other moving metalmust not touch. They must be continuously separated by a thin film of lubricant. This pre-vents excessive wear and early failure. There for a gearbox runs partially filled with lubricant oil.

SELECTIVE TYPE GEAR BOXIt is the transmission in which any speed may be selected from the neutral position. In this typeof transmission neutral position has to be obtained before selecting any forward or reverse gear.Some selective type gear boxes are,1. Sliding mesh gear box2. Constant mesh gear box with positive dog clutch.3. Constant mesh gear box with synchromesh device.

1. SLIDING MESH GEAR BOXa) It is the simplest and oldest type of gear box.b) The clutch gear is rigidly fixed to the clutch shaft.c) The clutch gear always remains connected to the drive gear of countershaft.d) The other lay shaft gears are also rigidly fixed with it.e) Two gears are mounted on the main shaft and can be sliding by shifter yoke when shifter isoperated.f) One gear is second & top speed gear and the other is the first and reverse speed gears. Allgears used are spur gears.g) A reverse idler gear is mounted on another shaft and always remains connected to reversegear of counter shaft.

First Geara) By operating gearshift lever, the larger gear on main shaft is made to slide and mesh withfirst gear of countershaft.b) The main shaft t urns in the same direction as clutch shaft in the ratio of 3:1.

Second Geara) By operating gear shift lever, the smaller gear on the main shaft is made to slide and meshwith second gear of counter shaft.b) A gear reduction of approximately 2:1 is obtained.

Top Geara) By operating gearshift lever, the combined second speed gear and top speed gear is forced

27

axially against clutch shaft gear.b) External teeth on clutch gear mesh with internal teeth on top gear and the gear ratio is 1:1.

Reverse Geara) By operating gearshift lever, the larger gear of main shaft is meshed with reverse idler gear.b) The reverse idler gear is always on the mesh with counter shaft reverse gear. Interposing theidler gear, between reverse and main shaft gear, the main shaft turns in a direction opposite toclutch shaft.

Neutral Geara) When engine is running and the clutch is engaged, clutch shaft gear drives the drive gear ofthe lay shaft and thus lay shaft also rotates.b) But the main shaft remains stationary as no gears in main Shaft is engaged with lay shaftgears.

CONSTANT MESH GEAR BOXa) In this type of gearbox, all the gears of the main shaft arein constant mesh with correspondinggears of the countershaft.b) The gears on the main shaft which are bushed are free to rotate.c) The dog clutches are provided on main shaft.d) The gears on the lay shaft are, however, fixed.e) When the left Dog clutch is slide to the left by means of the selector mechanism, its teeth areengaged with those on the clutch gear and we get the direct gear.f) The same dog clutch, however, when slide to right makes contact with the second gear andsecond gear is obtained.g) Similarly movement of the right dog clutch to the left results in low gear and towards rightin reverse gear. Usually the helical gears are used in constant mesh gearbox for smooth andnoiseless operation.

Advantage over sliding mesh gear box� Helical and herringbone gear can be used in these gear boxes and therefore, constant meshgearboxes are quieter.� Since the gears are engaged by dog clutches, if any damage occurs while engaging the gears,the dog unit members get damaged and not the gear wheels.Double declutching� Used for smooth downshifting.

2. SYNCHROMESH GEARBOXThis type of gearbox is similar to the constant mesh type gear box.a) Instead of using dog clutches here synchronizers are used.b) The modern cars use helical gears and synchromesh devices in gearboxes, that synchronizethe rotation of gears that are about to be meshed

SYNCHRONIZERSa) This type of gearbox is similar to the constant mesh type in that all the gears on the mainshaft are in constant mesh with the corresponding gears on the lay shaft.b) The gears on the lay shaft are fixed to it while those on the main shaft are free to rotate onthe same.c) Its working is also similar to the constant mesh type, but in the former there is one definiteimprovement over the latter.d) This is the provision of synchromesh device which avoids the necessity of double- declutching.

28

e) The parts that ultimately are to be engaged are first brought into frictional contact, whichequalizes their speed, after which these may be engaged smoothly.f) Figure shows the construction and working of a synchromesh gearbox. In most of the cars,however, the synchromesh devices are not fitted to all the gears as is shown in this figure.g) They are fitted only on the high gears and on the low and reverse gears ordinary dog clutchesare only provided.h) This is done to reduce the cost.Note:-The Model Gear Box Is Synchromesh Gear Box with 3 Forward and Single Reverse Gear.Some Other Transmission Used In Modern AutomobileTRANSFER CASE

� Normally used in 4 wheel drive vehicles.

� Two speed transmission having ”low and high” rear ratios that can be engaged while inneutral position.

� Fixed after the gear box.

� Enables engagement and disengagement of 4 wheel drive.

TRANSAXLE GEAR BOX

� Have only 2 shafts.

� Used in vehicle with engine and drive on some side.

– Font engine front wheel drive.

– Rear engine rear wheel drive.

� Most commonly used.

� Gear box and differential in same housing.

� Combination of transmission and differential in one unit is called transaxle.

� Transaxles are both automatic and manual.

10.4 PROCEDURE:

1. Plot a, b,c as in the ground.

2. The length of ab, bc and ac are given. It forms a triangle.

3. The alidade place along CA.

4. The board rotates till the point A is sighted and the board is clamped.

5. Pivot the alidade on a and sight to b and draw a ray .These two ray will meet at a point

6. Then joint bd, and rotate the board till the point B is sighted and draw a back ray.

7. This ray will meet at a point on the line bd, this will be the required station.

10.5 RESULT

The required instrument station C is occupied by using three point problem

29

LAB-10 TRAVERSING BY PLANE TABLE SURVEY

11.1 OBJECTIVE:

� To study the forced vibration of the beam for different damping.

11.2 RESOURCES:

� Vibration test rig� Cantilever Beam� Rubber hammer

11.3 PRECAUTIONS:

1. Do not run the motor at low voltage i.e. less than 180 volts.

2. Do not increase the speed at once.

3. Damper is always in perpendicular direction.

4. A motor bolts is properly tightly with weight.

5. A beam is proper tight in bearing with bolt.

6. Always keep the apparatus free from dust.

11.4 PROCEDURE:

1. Arrange the setup

2. Connect the exciter motor to control panel.

3. Start the motor and allow the system to vibrate.

4. Wait for 5 minutes for amplitude to build up for particular forcing frequency.

5. Adjust the position of strip chart recorder. Take the recorder of amplitude vs. Time onstrip chart recorder by starting recorder motor.

6. Take record by changing forcing frequency for each damping.

7. Repeat the experiment for different damping.

30

11.5 GRAPH:

� Plot the graph of amplitude Vs. Frequency for each damping

11.6 RESULTS:

Traversing method for running survey lines of a closed or open traverse is done.


1. Define free vibrations.

2. Define forced vibrations.

3. Define torsional vibrations.

4. Define longitudinal vibrations.

5. Define frequency related to vibratory motion.

31

Lab Manual: SURVEYING AND GEOMATICS LABORATORY ...

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